fix: GST on freight charge in e-invoicing (#25000)

* fix: GST on freight charge in e-invocing

* fix: Add patch for taxable value field

* fix: Handle discounts on net total

* fix: Handle all types of discounts for e-invoicing

* fix: Absolute taxable values

* fix: Use correct tax amount

erpnext/hooks.py

@@ -262,7 +262,8 @@ doc_events = {
 		],
 		"on_trash": "erpnext.regional.check_deletion_permission",
 		"validate": [
-			"erpnext.regional.india.utils.validate_document_name"
+			"erpnext.regional.india.utils.validate_document_name",
+			"erpnext.regional.india.utils.update_taxable_values"
 		]
 	},
 	"Purchase Invoice": {

erpnext/patches.txt

@@ -763,5 +763,6 @@ erpnext.patches.v13_0.setup_gratuity_rule_for_india_and_uae
 erpnext.patches.v13_0.setup_uae_vat_fields
 execute:frappe.db.set_value('System Settings', None, 'app_name', 'ERPNext')
 erpnext.patches.v13_0.rename_discharge_date_in_ip_record
+erpnext.patches.v12_0.create_taxable_value_field
 erpnext.patches.v12_0.add_gst_category_in_delivery_note
 erpnext.patches.v12_0.purchase_receipt_status

erpnext/patches/v12_0/create_taxable_value_field.py

@@ -0,0 +1,18 @@
+from __future__ import unicode_literals
+import frappe
+from frappe.custom.doctype.custom_field.custom_field import create_custom_fields
+
+def execute():
+	company = frappe.get_all('Company', filters = {'country': 'India'})
+	if not company:
+		return
+
+	custom_fields = {
+		'Sales Invoice Item': [
+			dict(fieldname='taxable_value', label='Taxable Value',
+				fieldtype='Currency', insert_after='base_net_amount', hidden=1, options="Company:company:default_currency",
+				print_hide=1)
+		]
+	}
+
+	create_custom_fields(custom_fields, update=True)

erpnext/regional/india/e_invoice/utils.py

@@ -171,10 +171,15 @@ def get_item_list(invoice):
 		item.description = sanitize_for_json(d.item_name)
 
 		item.qty = abs(item.qty)
-		item.discount_amount = 0
+
-		item.unit_rate = abs(item.base_net_amount / item.qty)
+		if invoice.apply_discount_on == 'Net Total' and invoice.discount_amount:
-		item.gross_amount = abs(item.base_net_amount)
+			item.discount_amount = abs(item.base_amount - item.base_net_amount)
-		item.taxable_value = abs(item.base_net_amount)
+		else:
+			item.discount_amount = 0
+
+		item.unit_rate = abs((abs(item.taxable_value) - item.discount_amount)/ item.qty)
+		item.gross_amount = abs(item.taxable_value) + item.discount_amount
+		item.taxable_value = abs(item.taxable_value)
 
 		item.batch_expiry_date = frappe.db.get_value('Batch', d.batch_no, 'expiry_date') if d.batch_no else None
 		item.batch_expiry_date = format_date(item.batch_expiry_date, 'dd/mm/yyyy') if item.batch_expiry_date else None
@@ -211,7 +216,7 @@ def update_item_taxes(invoice, item):
 
 			item_tax_rate = item_tax_detail[0]
 			# item tax amount excluding discount amount
-			item_tax_amount = (item_tax_rate / 100) * item.base_net_amount
+			item_tax_amount = (item_tax_rate / 100) * item.taxable_value
 
 			if t.account_head in gst_accounts.cess_account:
 				item_tax_amount_after_discount = item_tax_detail[1]
@@ -232,10 +237,14 @@ def get_invoice_value_details(invoice):
 	invoice_value_details = frappe._dict(dict())
 
 	if invoice.apply_discount_on == 'Net Total' and invoice.discount_amount:
-		invoice_value_details.base_total = abs(invoice.base_total)
+		# Discount already applied on net total which means on items
-		invoice_value_details.invoice_discount_amt = abs(invoice.base_discount_amount)
+		invoice_value_details.base_total = abs(sum([i.taxable_value for i in invoice.get('items')]))
+		invoice_value_details.invoice_discount_amt = 0
+	elif invoice.apply_discount_on == 'Grand Total' and invoice.discount_amount:
+		invoice_value_details.invoice_discount_amt = invoice.base_discount_amount
+		invoice_value_details.base_total = abs(sum([i.taxable_value for i in invoice.get('items')]))
 	else:
-		invoice_value_details.base_total = abs(invoice.base_net_total)
+		invoice_value_details.base_total = abs(sum([i.taxable_value for i in invoice.get('items')]))
 		# since tax already considers discount amount
 		invoice_value_details.invoice_discount_amt = 0
 
@@ -256,7 +265,11 @@ def update_invoice_taxes(invoice, invoice_value_details):
 	invoice_value_details.total_igst_amt = 0
 	invoice_value_details.total_cess_amt = 0
 	invoice_value_details.total_other_charges = 0
+	considered_rows = []
+
 	for t in invoice.taxes:
+		tax_amount = t.base_tax_amount if (invoice.apply_discount_on == 'Grand Total' and invoice.discount_amount) \
+						else t.base_tax_amount_after_discount_amount
 		if t.account_head in gst_accounts_list:
 			if t.account_head in gst_accounts.cess_account:
 				# using after discount amt since item also uses after discount amt for cess calc
@@ -264,12 +277,26 @@ def update_invoice_taxes(invoice, invoice_value_details):
 
 			for tax_type in ['igst', 'cgst', 'sgst']:
 				if t.account_head in gst_accounts[f'{tax_type}_account']:
-					invoice_value_details[f'total_{tax_type}_amt'] += abs(t.base_tax_amount_after_discount_amount)
+
+					invoice_value_details[f'total_{tax_type}_amt'] += abs(tax_amount)
+				update_other_charges(t, invoice_value_details, gst_accounts_list, invoice, considered_rows)
 		else:
-			invoice_value_details.total_other_charges += abs(t.base_tax_amount_after_discount_amount)
+			invoice_value_details.total_other_charges += abs(tax_amount)
 
 	return invoice_value_details
 
+def update_other_charges(tax_row, invoice_value_details, gst_accounts_list, invoice, considered_rows):
+	prev_row_id = cint(tax_row.row_id) - 1
+	if tax_row.account_head in gst_accounts_list and prev_row_id not in considered_rows:
+		if tax_row.charge_type == 'On Previous Row Amount':
+			amount = invoice.get('taxes')[prev_row_id].tax_amount_after_discount_amount
+			invoice_value_details.total_other_charges -= abs(amount)
+			considered_rows.append(prev_row_id)
+		if tax_row.charge_type == 'On Previous Row Total':
+			amount = invoice.get('taxes')[prev_row_id].base_total - invoice.base_net_total
+			invoice_value_details.total_other_charges -= abs(amount)
+			considered_rows.append(prev_row_id)
+
 def get_payment_details(invoice):
 	payee_name = invoice.company
 	mode_of_payment = ', '.join([d.mode_of_payment for d in invoice.payments])

erpnext/regional/india/setup.py

@@ -127,6 +127,9 @@ def make_custom_fields(update=True):
 	is_non_gst = dict(fieldname='is_non_gst', label='Is Non GST',
 		fieldtype='Check', fetch_from='item_code.is_non_gst', insert_after='is_nil_exempt',
 		print_hide=1)
+	taxable_value = dict(fieldname='taxable_value', label='Taxable Value',
+		fieldtype='Currency', insert_after='base_net_amount', hidden=1, options="Company:company:default_currency",
+		print_hide=1)
 
 	purchase_invoice_gst_category = [
 		dict(fieldname='gst_section', label='GST Details', fieldtype='Section Break',
@@ -460,7 +463,7 @@ def make_custom_fields(update=True):
 		'Supplier Quotation Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
 		'Sales Order Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
 		'Delivery Note Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
-		'Sales Invoice Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
+		'Sales Invoice Item': [hsn_sac_field, nil_rated_exempt, is_non_gst, taxable_value],
 		'Purchase Order Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
 		'Purchase Receipt Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],
 		'Purchase Invoice Item': [hsn_sac_field, nil_rated_exempt, is_non_gst],

erpnext/regional/india/utils.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 import frappe, re, json
 from frappe import _
 import erpnext
-from frappe.utils import cstr, flt, date_diff, nowdate, round_based_on_smallest_currency_fraction, money_in_words, getdate
+from frappe.utils import cstr, flt, cint, date_diff, nowdate, round_based_on_smallest_currency_fraction, money_in_words, getdate
 from erpnext.regional.india import states, state_numbers
 from erpnext.controllers.taxes_and_totals import get_itemised_tax, get_itemised_taxable_amount
 from erpnext.controllers.accounts_controller import get_taxes_and_charges
@@ -832,3 +832,48 @@ def get_regional_round_off_accounts(company, account_list):
 	account_list.extend(gst_account_list)
 
 	return account_list
+
+def update_taxable_values(doc, method):
+	country = frappe.get_cached_value('Company', doc.company, 'country')
+
+	if country != 'India':
+		return
+
+	gst_accounts = get_gst_accounts(doc.company)
+
+	# Only considering sgst account to avoid inflating taxable value
+	gst_account_list = gst_accounts.get('sgst_account', []) + gst_accounts.get('sgst_account', []) \
+		+ gst_accounts.get('igst_account', [])
+
+	additional_taxes = 0
+	total_charges = 0
+	item_count = 0
+	considered_rows = []
+
+	for tax in doc.get('taxes'):
+		prev_row_id = cint(tax.row_id) - 1
+		if tax.account_head in gst_account_list and prev_row_id not in considered_rows:
+			if tax.charge_type == 'On Previous Row Amount':
+				additional_taxes += doc.get('taxes')[prev_row_id].tax_amount_after_discount_amount
+				considered_rows.append(prev_row_id)
+			if tax.charge_type == 'On Previous Row Total':
+				additional_taxes += doc.get('taxes')[prev_row_id].base_total - doc.base_net_total
+				considered_rows.append(prev_row_id)
+
+	for item in doc.get('items'):
+		if doc.apply_discount_on == 'Grand Total' and doc.discount_amount:
+			proportionate_value = item.base_amount if doc.base_total else item.qty
+			total_value = doc.base_total if doc.base_total else doc.total_qty
+		else:
+			proportionate_value = item.base_net_amount if doc.base_net_total else item.qty
+			total_value = doc.base_net_total if doc.base_net_total else doc.total_qty
+
+		applicable_charges = flt(flt(proportionate_value * (flt(additional_taxes) / flt(total_value)),
+			item.precision('taxable_value')))
+		item.taxable_value = applicable_charges + proportionate_value
+		total_charges += applicable_charges
+		item_count += 1
+
+	if total_charges != additional_taxes:
+		diff = additional_taxes - total_charges
+		doc.get('items')[item_count - 1].taxable_value += diff